- 1 [uncountable, countable] a thick sweet substance made by boiling fruit with sugar, often sold in jars and spread on bread strawberry jam recipes for jams and preserves (British English) a jam doughnut compare jelly, marmalade many people/vehicles
- 2[countable] a situation in which it is difficult or impossible to move because there are so many people or vehicles in one particular place The bus was delayed in a five-mile jam. As fans rushed to leave, jams formed at all the exits. We were stuck in a jam for an hour. see also traffic jam See related entries: Motoring problems and accidents machine
- 3[countable] a situation in which a machine does not work because something is stuck in one position There's a paper jam in the photocopier. See related entries: How machines work Word Originnoun senses 2 to 3 early 18th cent.: probably symbolic; compare with cram noun sense 1 mid 18th cent.: perhaps from jam (verb).Idioms (informal) to be in a difficult situation (British English, informal) good things that are promised for the future but never happen They refused to settle for a promise of jam tomorrow. (British English, informal) money that is earned very easily, for something that needs little effort The job only took about an hour—it was money for old rope.